This relates to an apparatus for delivering a metered amount of liquid additive to a porous plug, such as a cigarette filter attached to a tobacco column.
It is known to provide cigarettes with additives such as flavors or sensory stimulants, such as menthol for example, at the time of cigarette manufacture. A shortcoming of such a practice is that the intensity of the additive can fade over time, whereby the benefits to the consumer are diminished and not consistent from cigarette pack to cigarette pack. Also, in the case of additives applied directly to the tobacco, the additive may be burned or pyrolyzed as the cigarette is smoked, whereby its effect is minimized.
Moreover, cigarette filters may contain adsorbents for the removal of gas-phase constituents produced from the burning end of the cigarette. For instance, if menthol is used as the additive in a carbon laden filter, it is possible for the carbon to adsorb the menthol, thus reducing the availability of menthol to the mainstream smoke and also reducing the capacity of the carbon to adsorb the gas phase constituents in the smoke.
Thus, there is a need to maximize the effect of cigarette additives without reducing the capacity of adsorbents to adsorb gas-phase constituents from mainstream smoke.
There is also a need to ensure that the effect of the additive is not diminished before the cigarette is smoked, and be consistent from one cigarette pack to another.